Submarine fans are sedimentary results that gravity flow transports shelf and upper slope sediments to deep-sea plains.These sediments can not only accumulate large amounts of oil and gas resources，but can also archive enormous amounts of climatic and regional structural information.Therefore，the study on the identification and development characteristics of the submarine fan has both scientific and practical significance.Using the newly acquired large amount of 3D seismic data，combined with drilling and REE data，the developmental characteristics and sediment sources of the submarine fans in the Baodao and Changchang Depression of the Qiongdongnan Basin are analyzed，and the main factors affecting the development and distribution of the submarine fans in the deepwater area are summarized.According to the sedimentary microfacies combination，there are three types of submarine fans，which include deepwater canyon-lobe，deepwater channel-lobe，deepwater channelized submarine fan developed in the Baodao and Changchang Depression of the Qiongdongnan Basin during the Middle Miocene.The submarine fan which consists of the canyon and lobe and deepwater channelized fan are located in the north part of the Baodao and Changchang Depression，and the provenance is Hainan Island.The submarine fan consisting of the deepwater channel and lobe is located in the south part of the Changchang Depression，and the provenance is Yongle Uplift.The main factors affecting the development and distribution of the submarine fan in the Middle Miocene of the Baodao and Changchang Depression include continental shelf topography and paleo-water depth，slope break type，paleo-seabed topography and relative sea-level decline.